Back in the vintage era when they referred to ham it was what we call "Country Ham" or "Virginia Ham" today. These hams are heavily salted before smoking and are not injected with any flavorants or water to make them juicy. Sometime in the 30's though Swifts brought about the ham revolution with the more modern process of injecting their hams with flavors and pre-baking them. It was a great time saver over the older method of cooking a ham which involved soaking and par boiling the ham to remove some of the salt before baking in the oven. Swifts hams also were juicier than the old country hams because they were not smoked and dry cured.
All this convenience has a price though as the flavorings injected are quite artificial and over the years Americans have developed something of a sweet tooth when it comes to ham so increasingly large amounts of sugar have been added to hams with the sugar eventually being replaced by High Fructose Corn Syrup by some companies. I remember when I was a kid and ham tasted like ham, a bit salty, maybe a slight bit sweet but not cloyingly so. Today though everyone seems to want to copy Heavenly Hams and their overpriced sticky sweet monstrosities.
If you hunt around you can still find country ham, usually in slices but if you're lucky you may stumble upon a whole one. These hams need to be parboiled 5 minutes a pound then let to sit several hours before removing and rinsing. Score the fat and then cook in a moderate oven for about half an hour before serving.